Abstract
Over 250 samples of Atlantic seawater have been analyzed for the dissolved helium isotopes, and distinctive pattern has emerged. Two components of excess 3He are seen: a component due to in situ decay of nuclear-era tritium, and a primordial component evolved from the solid Earth. A prominent feature at about 3-km depth can be traced from 5°N along the western boundary to the equator. The source of this feature is most probably in the Gibbs fracture zone, where we suppose that primordial 3He is released into westward-flowing bottom water. The South Atlantic profiles clearly show the effect of 3He-rich CCircumpolar Water, entrained by Antarctic Intermediate Water flowing northward. The excess 3He in the upper 1 km, when combined with tritum concentrations measured byO¨stlund, Dorsey and Rooth (1974, Earth and Planetary Science Letters, 23, 69–86) at the same locations and depths, yields ‘tritium-helium ages’, which in some cases represent the time interval between equilibration wwith the atmosphere and sampling.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.